Sand Land (PS5PRO): 'Bottle Land' Side Quest
The 'Bottle Land' side quest is pivotal in expanding the Junk Store' inventory.
To unlock it, you must complete the main story and the side quest 'Esteemed Architect'.
Talk to Gite and Hugh at the Junk Store to start the quest. You need to find 10 plastic bottles for Hugh. The plastic bottles appear in variou places in the game.
I played blindly which is why it took a while to find all 10 Plastic Bottles. Once I did, I gave em to Hugh to complete the quest. The Junk Store's inventory is increased and it also unlocks the side quest 'A Voice Calling for Help'.